Careful on what species of nerite too as some will crawl out of the tank and along your living room floor before they die not finding their way back. Get the ones that don't live on the waterline. Good vendors will clarify which ones they sell.
Aim for the tongan (sometimes called jumbo) nassarius, and avoid the ilyanassa obsoletta sometimes called nassarius == mistakenly. Avoid bumblebees. The tongan nass are great ... bigger, meaning better sandsifters, and much, much longer-lived. One per 5 gallons no more.
Ceriths will breed in a tank with good conditions, so you can either get one per 2 gallons or one per 5 and let them reproduce.
Ceriths and nass are a must.
Avoid Astraeas and Turbos and get true Trochus sp. They, unlike the others, will live. One per 10gal is a good rule.
Get a couple fighting conch for the sandbed. And, if you can find them, stomatellas.
If you get hermits, go with scarlet reef hermits and avoid redleg and blueleg as they are predators of snails.
Since you are in the US, I highly recommend Premium Aquatics as a vendor for these. You can go reeftopia if you have a few others to join you in a lot order. But you wont' find Trochus there...
If the tank is new or you have never done it, a Mix 'n' Match from the best, Inland Pacific www.ipsf.com, is a really good idea.